


Hair of a Different Color

by popatochisp



Category: Undertale (Video Game)
Genre: Affection, Alternate Universe - Horrortale (Undertale), Alternate Universe - Swapfell (Undertale), Alternate Universe - Underfell (Undertale), Alternate Universe - Underswap (Undertale), Cuddling & Snuggling, Cute, Established Relationship, Ever - Freeform, F/M, Flirting, Fluff, Gender-Neutral Pronouns, Hair Dyeing, Horrortale Papyrus (Undertale), Horrortale Sans (Undertale), Hurt/Comfort, M/M, Other, Running out of tags to indicate that I am a total softie and love to write about Good Things, Suggestive Themes, Swapfell Papyrus (Undertale), Swapfell Sans (Undertale), Underfell Papyrus (Undertale), Underfell Sans (Undertale), Underswap Papyrus (Undertale), Underswap Sans (Undertale), everything is soft and cute and nothing hurts
Language: English
Status: Completed
Published: 2019-01-09
Updated: 2019-01-09
Packaged: 2019-10-07 04:45:37
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings, No Archive Warnings Apply
Chapters: 10
Words: 2,941
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17359223
Author URL: https://archiveofourown.org/users/popatochisp/pseuds/popatochisp
Summary: Inspired by a tumblr ask that posed the following: "What if the skeles had a SO that dyed their hair pretty frequently. One day they dye their hair color to the skeles magic color saying, " it's my favorite color now since it reminds me of my favorite skeleton!""If you're interested in a Sans or Papyrus from Undertale, Underswap, Underfell, Swapfell, or Horrortale, there's a chapter in here for you! ;)





	1. Cyan (UT!Sans)

“Hey. Sans.”

“mmmnngrh.”

You grin at the lump on the couch that is your boyfriend—not that he can see it, facing the other way like that.

“I finished dyeing my hair,” you tell him.

“looks great,” he mutters into a pillow.

You have to stifle a snicker. “You wanna actually _look_ at it, or…?”

Sans heaves a very dramatic and put upon sigh and drags himself sorta upright, scrubbing a hand over his face.

“i _guess_ so, if i gotta,” he mumbles. “y’know i’m winnin’ ‘datemate of the year’ award over hhhhhhello. _wow_.”

You give up trying not to laugh. Sans’ surprised expression is too funny, his eye-lights locked onto your unnaturally bright cyan hair.

“Do you like it?” you ask, unable to contain your excitement. You even shoot his own signature wink at him as you teasingly quip, “It reminded me of my _favorite_ skeleton!”

“……heheheheh, aw, jeez…” Sans’ cheekbones flush with just the barest hint of color, the very same shade that’s on your head now. “you sure know how to make a guy feel special, don’tcha? c’mere, you.”

Figures: you dye your hair to match his magic and he won’t even get up off the couch to kiss you.

But…he’s smiling at you like you gave him a gift and his open arms are just too inviting to turn down, so…

Ah, why not? You could go for a couch cuddle right about now, anyway!

**Notes for the Chapter:**

> [Fanart](https://popatochisssp.tumblr.com/post/185821612343/saphiredawns-world-wait-no-june-heheh-come) by saphiredawns-world


	2. Cobalt Blue (UT!Papyrus)

He’s been staring at you for at _least_ thirty seconds.

You’d hoped to catch him by surprise with this little change of yours, but this?

This was starting to verge on _awkward_.

“Uhhh…Papyrus?” you hesitantly wonder. “Is it…do you… I mean, uh, what do you…think?”

Papyrus seems to jolt a little at your words, blinking his impossible eye-sockets.

They’re starting to look kind of…shiny?

“YOU’RE BLUE NOW!” Papyrus finally exclaims, breaking his silence. “AND I—NYEH-HEH-HEH—I DIDN’T EVEN HAVE TO USE MY MAGIC!”

That surprises a laugh out of you.

“Oh man,” you chuckle, “you had me worried you didn’t like it or something!”

“‘LIKE IT’?!” Papyrus echoes, sounding almost offended. “I DON’T _LIKE_ IT AT ALL!”

Your smile starts to drop.

“I _LOVE_ IT!”

………

Stars above, _Papyrus_ …!

You have half a mind to yell at him for making you feel like an emotional yo-yo, but the other half…

Well, Papyrus wouldn’t be your boyfriend if you didn’t love his bony butt to bits!

So when he turns those shiny, excited eye-sockets onto your cobalt hair and eagerly asks, “CAN I PLAY WITH IT???” you really only have one answer to give.

“Go for it!”

**Notes for the Chapter:**

> [Fanart](https://popatochisssp.tumblr.com/post/185742170738/saphiredawns-world-your-room-is-a-mess-if) by saphiredawns-world


	3. Sky Blue (US!Sans)

 

“HELLO, DARLING! I’D LOVE TO STAY FOR A MORE PROPER GREETING, BUT ALPHYS IS OUTSIDE, WE’RE GOING ON A RUN AND I FORGOT MYYYYYYYOUR _HAIR_!”

For all of Sans’ bragging that he could stop on a dime, you’d never actually seen him _do_ it before, literally freezing mid-sprint upstairs to stare at you, mouth agape.

It was probably as impressive as it was funny.

“Do you like it?” you wonder. “I bet you can guess the inspiration…”

Sans takes only a second to put it together. His sky blue eye-lights—a perfect match to your hair—blip rapidly between shapes at the realization and apparently his usual excited stars aren’t enough for this occasion.

You only catch a glimpse of the literal hearts in his eye-sockets before he _zooms_ over to you and scoops you right up off the ground.

“Sans?! What the hell!”

You can’t exactly blame him for not taking your indignant words seriously, laughing as you are, and his fierce nuzzling against your cheek just makes you laugh even harder.

“YOU’RE THE BEST,” he declares, as delighted as he is serious, “THE _BEST_ HUMAN, _MY_ DATEMATE…!”

Well, you can’t argue with that…though you could probably argue with the way he carries you over to the front door, kicks it open, and runs outside with you, if it wasn’t all happening so _fast_.

Alphys is out there in jogging gear, looking about as confused as you feel. “You’re bringing your human?” she asks. “What happened to getting your water bottle, Sans?”

“FUCK MY WATER BOTTLE,” Sans proclaims, “IT’S AN ENDURANCE RUN, ISN’T IT? I’M TAKING MY HUMAN INSTEAD—LOOK, WE MATCH!”

Alphys almost goes a little starry-eyed herself when she notices your hair and she hurriedly tries to pretend she doesn’t find it as cute as she actually does. “Pfft, okay, sure…why not! Just try to keep up!”

“YOU MEAN ‘DON’T OUTPACE YOU TOO EARLY AND EMBARRASS YOU’? I’LL CERTAINLY TRY!”

“Oh, you cocky little bag of bones, it’s _on_ now!”

And on it was, because there you go, carted off at impressive speeds by your stupidly strong boyfriend, with a smile on your face and the wind in your hair.

**Notes for the Chapter:**

> [Fanart](https://popatochisssp.tumblr.com/post/185900187353/saphiredawns-world-while-i-do-quite-enjoy-the) by saphiredawns-world


	4. Cerulean Blue (US!Papyrus)

Papyrus barely looked up from the checkout desk as a handful of books were slid into his line of vision, library card already on top for maximum convenience—just the way he liked it.

“just these?”

“Mmm, no, I was hoping for a little something else, too.”

Oh, that voice was familiar, and so was the name on that library card, but when he perked up to greet his datemate with a smile, his eye-sockets go wide.

That brand new hair color you were sporting was _not_ familiar at all.

On second thought, though…maybe it _was_ …

“oh, very sorry,” Papyrus drawled, tugging the stack of books away from you. “you can’t check these out, not ‘til you pay all your overdue fees.”

You playfully frown at him. “ _What_ fees?” you demand. “You’re trying to railroad me! I don’t have any fees!”

Papyrus pretends to check something on the computer, solving that one last word jumble real quick before looking back up as embarrassed and apologetic as he could fake.

“my mistake,” he admits, “you’re absolutely right. guess i just got confused—you’ve got ‘ _fine’_ written all over you.”

“…pfft! Hahaha, _Papyrus…_!”

Ahh, your laughter: music to the ears he didn’t have and making you look even more stunning than that gorgeous cerulean hair that you just _had_ to have dyed for him…

You’re adorable.

……but you _are_ laughing in a library, so really, he has no choice.

“shhhh, it’s a _library_ , y’know.”

Your whispered, “Oh, shut up!” is almost as cute as you.

**Notes for the Chapter:**

> [Fanart](https://popatochisssp.tumblr.com/post/185821585108/saphiredawns-world-yer-an-ass-you-know-that) by saphiredawns-world


	5. Candy Apple Red (UF!Sans)

You frown a little when you see Sans with his face in his hand, his shoulders slumped and his claws rubbing at his skull; the way he always did when he felt a headache coming on.

“Aw, rough day, baby?” you ask quietly.

Sans only tenses for a second when he realizes he hadn’t heard you come in. He’s gotten _that_ used to you by now and you can’t help but feel a little proud of it when he just sighs, not even looking up.

“too long,” is all he grumbles at you, and…

Well.

You can’t just let _that_ be, can you?

You go over to him and lay your hands on those broad shoulders you love so much, rubbing at them through his jacket. You have no idea how a massage works for somebody who doesn’t have any muscles, but it always seemed to help Sans out a little when you did it so you just keep at it.

He lets you for good long while before he reluctantly starts to shrug you off.

“alright, alright,” he huffs, “that’s good enough… thanks d—………”

You grin reflexively under his wide-eyed stare, ruffling your fingers through your newly-dyed hair: bright, candy apple red to match Sans’ magic.

“Surprise…?” you say a little sheepishly.

You’d have saved this reveal for another day if you’d known Sans maybe wasn’t feeling well, but c’est la vie, you guess.

It suddenly seems like Sans has forgotten all about his headache, though, slowly drifting to his feet and raising his hand to your hair.

“ _doll_ ,” he breathes, and his claws against your scalp make you shiver. “…ya’ did this fer _me_?”

Your cheeks heat a little but…you can’t exactly _deny_ it and your nod seems to spark a fire behind Sans’ eye-lights, red as your hair and glowing with excitement.

“yer too sweet,” he smirks at you. “guess i oughta do somethin’ nice fer you, too, huh?”

When Sans leans in, you’re happy to meet him halfway.

Maybe your timing wasn’t so bad, after all…

**Notes for the Chapter:**

> [Fanart](https://popatochisssp.tumblr.com/post/185821664413/saphiredawns-world-yes-jasper-how-dare-you-tell) by saphiredawns-world


	6. Crimson Red (UF!Papyrus)

“HUMAN, WHERE ARE YOU AND _WHAT_ HAVE YOU DONE TO THE SINK?! AND DO YOU NEED BANDAGES OR HELP WITH A BODY BECAUSE YOUR ANSWER! WILL GREATLY IMPACT MY ANNOYANCE LEVELS AT THIS MESS!”

Oh damn, you knew you’d forgotten _something_.

You could kick yourself for not cleaning up after your latest dye-job, or even _considering_ how it might look to leave a bunch of wet crimson streaks all over the sink and then wander off, nowhere to be found.

You’d just wanted it to be a _surprise_ …

“I’m here!” you call out to Papyrus, and you hear his rapidly approaching footsteps even before you finish talking. “It’s not blood, just dye, I’ll help you clean it up—”

“YOU’LL CLEAN IT UP YOURSELF!” Papyrus demands, bursting into your room with all the gravitas of a captain—fitting for the uniform he was still wearing, straight from the Royal Embassy. “IT’S THE _LEAST_ YOU CAN DO TO MAKE UP FOR LEAVING SUCH A DISTURBING MESS AND MAKING _ME,_ THE GREAT AND TERRIBLE PAPYRUS, THINK FOR EVEN A _SECOND_ THAT—THAT…OH.”

You have to toss your head a little, giving your hair a flip to show off the brand new color to the skeleton who inspired it.

You…may be a bit smug about the slack-jawed look he’s giving you.

“‘Made you think’ what?” you ask coyly, teasing Papyrus for his lost train of thought.

You don’t think it bruises his ego _too_ badly, though, not with the way he wordlessly pounces you onto your mattress and starts guiding your hands to all the hidden clasps and ties of his uniform.

Something tells you he _likes_ your new hair.

**Notes for the Chapter:**

> [Fanart](https://popatochisssp.tumblr.com/post/184465255658/saphiredawns-world-i-found-a-cute-fanfiction-a) by saphiredawns-world


	7. Electric Purple (SF!Sans)

You’re losing your mind.

You must be, because you _definitely_ left the dye box _right here_ under the sink and now it’s just…not.

Boxes don’t just get up and walk away, so where the hell could it _be_? And how were you supposed to surprise your boyfriend with it now?

Sans wasn’t going to be out of the house forever!

…or at _all_ apparently, you discover as you turn around to find the skeleton himself right behind you.

You jump a little to see him so close and your frustration about the dye makes you…maybe a little bit snappish.

“Sans! Don’t sneak up on me like that!” you chastise him. “What if I was…in the middle of something?”

“OH, ‘SOMETHING’?” Sans echoes, sounding amused. “YOU MEAN PERHAPS… _THIS_ SORT OF ‘SOMETHING’?”

Your jaw drops.

The sight of the purple hair-dye in Sans’ gloved claws fills you with equal parts dismay and annoyance.

Of _course_ that’s where it went, you think to yourself, knowing you should’ve known from the start: it went ‘missing’ right into your paranoid, hawk-eyed Sans’ talons.

You sigh, holding out your hand for it. “Okay, Mister Fun-Killer,” you grumble, “hand it over.”

Sans doesn’t.

“THIS? OH NO, YOU DON’T WANT THIS ONE.” So saying, he dumps the box into the trash like so much…well, like so much garbage, ignoring your ‘hey!’ of protest. “IT’S NOT EVEN THE RIGHT SHADE, DEAREST. CLOSE, BUT NOT QUITE— _THIS_ ONE IS MORE APPROPRIATE TO MATCH MY MAGIC, WOULDN’T YOU AGREE?”

………You would. The box Sans hands over to you is at least two shades brighter than the closest one you’d been able to find, a true electric purple like the lights shining happily at you from your boyfriend’s eye-sockets.

Sans is pleased as punch to help you with your hair and when it’s all said and done, you think you’re glad for his snooping and meddling, after all.

The two of you make a very charming pair in the mirror, perfectly color-coordinated and handsomely matching as he presses his shark-teeth to your cheek for a careful kiss.

**Notes for the Chapter:**

> Like everyone and their grandmother, I have my own version of the Swapfell AU in my head so here's a quick and dirty cheat-sheet based on the three most popular versions: aesthetics of SF Purple/SF Gold, personalities of SF Gold/SF Red.
> 
> -
> 
> [Fanart](https://popatochisssp.tumblr.com/post/184518968188/saphiredawns-world-i-found-a-cute-fanfiction-a) by saphiredawns-world


	8. Dusky Violet (SF!Papyrus)

You try not to laugh.

It’s hard, though, because Papyrus won’t _stop_ and it’s…it’s really starting to tickle at this point.

There’s definitely an undercurrent of a giggle in your voice as you ask, “Are you just gonna…nuzzle me forever, or…?”

“yeah,” Papyrus murmurs against the back of your skull. The word is muffled by the way he seems to be speaking directly into your dusky violet hair, not even pausing from his apparently very important…face-to-hair rubbing.

“You’re so _weird_ ,” you tell him, with no small amount of fondness.

His mouth dips down to your neck at your words. Out of the corner of your eye, you see his gold fang catching the light, even as he gently, carefully nibbles at you—the way he sometimes does instead of nuzzling.

For all you know, it could be the closest skeleton equivalent to a kiss.

“i love you,” he mumbles fervently against your pulse. “can’t believe i get to have you…you’re _amazing_ …”

Oh, jeez, what a sweetheart. If you’d known that dyeing your hair to match Papyrus’ magic would make him _even more_ cuddly than usual…

You’d have done it a lot sooner.

“I love you, too,” you’re happy to assure him.

It’s a little bit of a struggle getting him off you enough to turn and reciprocate his affection, and the only way you manage it is with his claws carding through your hair over and over and over again.

You’re gonna need a lot more dye.

**Notes for the Chapter:**

> Like everyone and their grandmother, I have my own version of the Swapfell AU in my head so here's a quick and dirty cheat-sheet based on the three most popular versions: aesthetics of SF Purple/SF Gold, personalities of SF Gold/SF Red.
> 
> -
> 
> [Fanart](https://popatochisssp.tumblr.com/post/184586337888/saphiredawns-world-i-found-a-cute-fanfiction-a) by saphiredawns-world


	9. Slate Blue (HT!Sans)

Sans always asks to do your hair for you, now.

You’re still getting used to it—he never showed this much interest in it _before_ …

But then, you suppose _before_ , your hair hadn’t been blue, the very same soft grayish shade of slate as you saw in his magic on those rare occasions that he showed it to you.

You see it a lot more now and not just on your head. It creeps across Sans’ cheekbones pretty often now, sometimes even just when he looks at you for long enough and you have to admit, it makes you a little giddy.

Sans is so _cute_ when he gets shy…

But still.

“You know you don’t _have_ to do my hair…right?” you ask him, watching his face in the mirror.

He truly towers over you and his hands look even more massive than usual busied in the strands of your slate blue hair. His blood-red eye-light stays focused on his task, but he still answers you.

“i know. i want to.”

Sans really does seem utterly enamored with the color you chose. Even when he stares at it a little _too_ long and makes himself blush the same shade—like now—he just can’t seem to turn away from your hair and how it looks between his fingers.

Your favorite is when that red eye-light of his warps into a heart shape. Sometimes, it’ll stay that way for whole _minutes_ at a time before he notices and tries to hide it from you like a big, embarrassed dork.

You certainly aren’t going to be the one to put an end to _that_.

Sans can play with your hair all he likes.

**Notes for the Chapter:**

> [Fanart](https://popatochisssp.tumblr.com/post/184910175158/saphiredawns-world-and-another-one-i-love-this) by saphiredawns-world


	10. Denim Blue (HT!Papyrus)

“I…You… For Me? You Did This For Me???”

Your cheeks are feeling a little hot. You didn’t expect Papyrus to actually call you _out_ on the new hair color you’d picked and now you’re wondering if it was a tad too much.

You just thought the shade of denim-blue magic you’d seen your boyfriend use was a cool color—it reminded you of him and you wanted to try wearing it out for a bit.

But the look Papyrus is giving you now, genuinely stunned and a little disbelieving…it’s starting to make you doubt yourself.

Was there…maybe a deeper significance toward wearing your partner’s magic color for monsters than you’d thought? Something that’s too personal or intimate for the relationship you have now?

You’re not sure and the uncertainty is making you nervous.

Should you apologize? Should you…

………

“Papyrus, are you…are you _crying_?”

“No!” he exclaims immediately, his voice suspiciously watery. “…Okay, Yes! A Little! But Only Because! You Look So Incredible In That Color! I Can’t Believe You Picked It For Me, You Really _Must_ Be The Sweetest, Most Thoughtful Human Ever!”

Your shoulders slump a little in relief and you smile up at your unfairly tall boyfriend. “If I am, it’s only because you’re the sweetest, most thoughtful skeleton ever!” you shoot back.

“That’s Not A Very Effective Compliment,” he gently points out to you. “There’s Only Two Of Us Skeletons, My Odds Of Winning That Contest By Chance Alone Are Enormous! Your Compliments Should Be More Merit-Based To Be Truly Empowering…But! I Accept It In The Spirit It Was Meant!”

Papyrus bends at the waist to nuzzle his teeth against your cheek. He’s so careful that his braces don’t even scrape you a little and it makes you smile.

“Okay, then,” you try, “how about…you’re my favorite person?”

Papyrus’ eye-sockets widen behind his glasses. “What,” he asks you, “Ever???”

You shrug a little playfully. “I’ve never dyed my hair to match somebody before. I’d say that probably makes you my favorite.”

“…O-Oh. I See!”

“Snrk…Papy, do you, uh…have something caught in your eye-socket?”

“Yes! And It’s Tears, Don’t Bother Asking Questions You Already Know The Answer To!”

Yeeep, you were sure of it now: Papyrus was _definitely_ your favorite!

**Notes for the Chapter:**

> Check out the [original post](https://popatochisssp.tumblr.com/post/181863283223/what-if-the-skeles-had-a-so-that-dyed-their-hair) for some visual aids! ;3
> 
> Thanks for reading, hope you enjoyed the fluff!
> 
> -
> 
> [Fanart](https://popatochisssp.tumblr.com/post/185821638028/saphiredawns-world-ok-paps-hhhhhhnnnngg-got) by saphiredawns-world


End file.
